Department of Botany, Program in Environmental Studies, Connecticut College, New London, CT 06320, USA.
Protist. 2013 Jul;164(4):541-55. doi: 10.1016/j.protis.2013.05.001. Epub 2013 Jun 19.
Well-preserved siliceous plates representing multiple species of euglyphids are described from a Middle Eocene maar lake deposit located near the Arctic Circle in northern Canada. Siliceous plate morphotypes including scutiform, rectangular, hexagonal, oval and circular body forms, six apertural plate types containing from five to thirteen teeth and spine plates, are documented. Many plate types bear resemblance to those found on modern species as well as ones documented from Miocene sites. These findings extend the known geological record for euglyphids and support the concept of evolutionary stasis in regards to plate morphology over much of the Cenozoic. Future use of these euglyphid remains, in conjunction with other microfossil assemblages, for reconstructing historical conditions within the maar lake is discussed.
在加拿大北极圈附近的一个中始新世玛尔湖沉积层中，发现了保存完好的硅质板，代表了多种 Euglyphidae 物种。描述了包括盾形、长方形、六边形、椭圆形和圆形身体形态在内的硅质板形态型，以及六种具有五到十三颗牙齿和刺板的口盖板类型。许多板型与现代物种以及中新世遗址记录的物种相似。这些发现扩展了 Euglyphidae 的已知地质记录，并支持了关于新生代大部分时期板形态进化停滞的概念。讨论了未来如何结合其他微化石组合，利用这些 Euglyphidae 遗骸来重建玛尔湖中历史条件的问题。
